Spectrum resources are basic medium of communications, but the spectrum resources are limited, which makes users hope that utilization rate of frequency spectrum can be improved furthest. The development of different radio access technologies is also to improve the utilization rate of frequency spectrum. However, the frequency spectrum and load switching between radio access technologies in the existing communication network are almost nonexistent, that is, almost no cooperative operations are existent between each other, which causes that usage of the frequency spectrum is relatively solidified and not flexible enough, and reduces the utilization rate of frequency spectrum. For example, frequency spectrum load of some radio access technologies are relatively light, but frequency spectrum load of some radio access technologies are relatively heavy, since there are no interaction and cooperation between the access technologies, flexible dynamic allocation of frequency spectrum can be not implemented. In order to solve this problem, the industry study the radio cognitive technology currently to implement dynamic adjustments of network through cognitive radio, which includes the adjustments of working parameters such as the radio access technology and frequency band in one region. However, the ultimate goal of the cognitive radio is to require that access can be implemented on different frequency bands with different radio access technologies and communications can be performed; it has very high requirements on the base station and terminal, even new network elements may be added in the existing network structure, and the technology is still at the study phase and has no complete achievable schemes currently.
In radio communication, an uplink service and a downlink service are generally asymmetric, and in normal conditions, downlink service traffic is greater than uplink service traffic. Therefore, in certain conditions (especially in a condition of symmetric uplink and downlink bandwidth), relatively surplus uplink system bandwidth and tensive downlink system bandwidth will occur. Specifically, in a Long Term Evolution Frequency Division Duplex (LTE FDD) system, the uplink bandwidth and downlink bandwidth are usually configured symmetrically, that is, the uplink bandwidth and downlink bandwidth are identical, which may cause idle uplink system bandwidth and then lead to a decreasing utilization rate of frequency spectrum, but the downlink frequency band are insufficient and has no frequency spectrum supplement. Similarly, in a few conditions, when uplink traffic is relatively heavy, insufficient uplink bandwidth will be caused, and if there is idle bandwidth in downlink, it will cause the utilization rate of downlink frequency spectrum to reduce in a fixedly configured network.
It can be seen that, adopting a fixed network configuration in the above scenarios can not optimize the use of frequency spectrum. In addition, the cognitive radio technology is still at the study phase and also does not consider a bandwidth coordination scenario with such kind of radio access technology. Therefore, utilization efficiency of frequency spectrum in the LTE FDD system needs to be further improved.